Erythema (Gr.Erythema 0600566 to redden), an affection of the skin characterized by a slight redness without determinate form. It is generally due to the action of some special cause, as the heat of the sun, etc. Where it is produced by the friction of two contiguous surfaces, as frequently occurs in infants and in fleshy persons, it is often called intertrigo. Erythema nodosum, the severest form of the disease, is characterized by the eruption of numerous red spots from one third of an inch to an inch in their longest (vertical) diameter. These spots are slightly elevated ; after a few days their color deepens, and passing through various shades of blue and yellow, the skin resumes its normal color. The affection is apt to be attended with fever, depression of strength, and derangement of the digestive organs. Simple erythema needs no treatment beyond the employment of soothing applications; in intertrigo, the use of an absorbent powder, as lycopodium, starch, etc, may be advisable.

Erythema nodosum is best treated by diet, rest, and a mild laxative; in some cases tonics and iron are useful.